Very irked

Wr bought a car by flexi drive last year on the 25th of October. The first debit order went of as arranged, since then 2 debit orders failed. One, i was told, due to a system glitch, the second im still waiting on a response. They email saying the debit order has failed and that we have 7 days to correct it, in other words, i have to pay the installment manually, wich costs me R35 every time, for immediate payment. I am very irked by this.